What do the stories about former beaus and secret panels in houses of the past relate about the Grandmother in "A Good Man is Hard to Find"?
The details about the grandmother serve to round out her character--I say "round out" rather than explain because the grandmother's nature inspires considerable critical debate. There are therefore a number of ways of reading or interpreting these details.
The story about the grandmother's former beau Mr. Teagarden is a seemingly unimportant anecdote, but it is rich with interpretative possibilities. First, like other incidents related in the story, the tale of Mr. Teagarden reveals the story's overall concern with memory and the past. As we learn, the grandmother's memory is imperfect and embellished.We see from the grandmother's description of Mr Teagarden and the carved watermelon a certain preoccupation with appearances, consumption (as suggested by the Coca-Cola stock), as well as a degree of racism. These details about the grandmother are complicated by the story's questioning of what constitutes goodness. Based on what we know, is the grandmother a good woman? The answer is certainly debatable.
The detail about the house with the secret panel likewise illustrates the story's larger preoccupation with memory and the past. Most obviously, this is shown through the grandmother's imperfect memory. Further, the secret panel suggests things hidden: lies, deceptions and half-truths that make a good man (or woman) hard to find.
These jaded memories are also indicative of a different time. The grandmother wants to live in the past, but times have changed drastically. The world is a much more difficult, dangerous place when the story is set compared to when the grandmother was an adolescent girl. The grandmother perhaps wishes things could be simpler now as they were then for her. She had few cares then and could concentrate on being wooed and courted instead of being crammed into a car with her son and his family!